AHFS Class:

76:00 Oxytocics

Generic Name

• Oxytocin (CAS Registry Number: 50-56-6)

Oxytocin is available as a 10-unit/mL injection solution in 1-mL single-dose vials, 10- or 30-mL multiple-dose vials, and 50-mL pharmacy bulk packages.²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸ Each mL contains oxytocin 10 units with chlorobutanol 0.5% as a preservative.²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸ Acetic acid may have been added for pH adjustment.²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸ Some products may contain acetic acid and ammonium acetate as buffers.²⁸⁵⁶; ²⁸⁵⁷

Units

One unit of oxytocin is equivalent to 2 to 2.2 mcg of pure oxytocin.⁴

pH

3.5²⁸⁵⁶; ²⁸⁵⁷ or from 3 to 5.²⁸⁵⁸

Trade Name(s)

Pitocin

Oxytocin is administered by intravenous infusion and, depending on the indication, may be administered by intramuscular injection.²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸ For induction or stimulation of labor, oxytocin should be administered only by intravenous infusion²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸ because the drug’s effects are unpredictable and difficult to control.⁴

For intravenous infusion for induction or stimulation of labor, product labeling recommends oxytocin injection be diluted to a usual concentration of 10 milliunits/mL by adding 10 units (1 mL) to 1000 mL of Ringer’s injection, lactated, or sodium chloride 0.9%.²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸ For other indications, product labeling states oxytocin may be diluted to a concentration of 20 milliunits/mL (1 mL in 500 mL) or up to 40 milliunits/mL in a compatible infusion solution.²⁸⁵⁶; ²⁸⁵⁷

Oxytocin injection is a clear, colorless solution.²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸ Visually inspect solutions for particulate matter or discoloration prior to use.²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸

Intact containers should be stored at controlled room temperature²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸ and protected from freezing.²⁸⁵⁸ Discard unused portions of the drug.²⁸⁵⁷; ²⁸⁵⁸

Oxytocin appears to be rapidly decomposed in the presence of sodium bisulfite.³³³

Freezing Solutions

Oxytocin (Teva) 0.02 unit/mL in sodium chloride 0.9% in polyolefin bags (B. Braun) was physically stable with less than 10% loss of drug when frozen at -20°C for 30 days, thawed, and allowed to come to room temperature.⁴¹¹⁴

Filtration

Oxytocin (Parke-Davis) 25 units/100 mL in dextrose 5% and sodium chloride 0.9% was filtered at about 3 mL/min through a 0.22-µm cellulose ester membrane filter (Ivex-2). At this concentration, 25 times higher than normally used, oxytocin appeared to bind initially to the filter from the sodium chloride 0.9% solution. Results in dextrose 5% were equivocal. From these data, it is not possible to draw a definite conclusion regarding substantial binding of oxytocin during normal usage.⁵³³

Standardize 4 Safety

One or more standardized concentrations for this drug have been established through Standardize 4 Safety (S4S), a national patient safety initiative to reduce medication errors, especially during transitions of care. (See Standardize 4 Safety in Users Guide.) Recommendations developed to date through this initiative are available at www.ashp.org/pharmacy-practice/standardize-4-safety-initiative.

Table 1. Standardize 4 Safety Continuous IV Infusion Standard Concentrations for Oxytocin³⁶³⁶

^aSee ISMP for best practices. www.ismp.org/resources/taking-closer-look-medication-errors-involve-oxytocin; www.ncbi.nlm.nih.gov/pmc/articles/PMC3956395/

Solution Compatibility

Additive Compatibility

Drugs in Syringe Compatibility

Y-Site Injection Compatibility (1:1 Mixture)

For a list of references cited in the text of this monograph, search the monograph titled References.

ASHP^® Injectable Drug Information^TM. Selected Revisions September 12, 2025. © Copyright, 2025. American Society of Health-System Pharmacists^®, 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.